I don't know, but I need an answer!
what is the third stage of the star cycle
Michael Capellas was born in 1955.
dust
The "main sequence".
stellar nebula
Xavier Capellas was born in 1962, in Rub, Barcelona, Catalonia, Spain.
Altair is still in the main sequence stage of a stars life. See related link for more information.
The young star stage because at that stage, stars are just burning, no interruptions or disturbances
For a star like ours, the black dwarf stage For an immensely massive star, a back hole.
No, it's a possible stage in the life cycle of a star.
Protostar!
You can tell by its size and/or color.